This invention relates generally to tanks for storing cryogenic fluids, and in particular to such a tank which includes means for resisting impact loads thereon and to serve as a secondary liquid containment for the cryogenic fluid.
There are many types of tanks known in the prior art for storing cryogenic fluids, and such tanks include both those comprising metal walls and those having concrete walls. Some prior art tanks include both metal and concrete walls. However, there is no cryogenic tank known to applicants which comprises both a metal inner tank for storing cryogenic fluid and a reinforced concrete outer tank or wall having means for resisting impact loads thereon to protect the inner tank and having seal means associated therewith to serve as a secondary containment for the cryogenic fluid.
Recently there has been increasing concern for providing some means in association with cryogenic storage tanks for protecting the tanks against impact loads thereon and to provide an effective liquid containment even in the event of rupture of the inner tank. For example, such tanks are becoming more common in urban areas, and the danger of a catastrophic explosion is great in such heavily populated areas in the event a large spill or leak of the cryogenic fluid occurs. For example, an explosion in the vicinity of the tank or a nearby crash of an airliner or the like could result in rupture of the wall of the tank, with the result that large amounts of the cryogenic fluid leak into the surrounding area, creating an extremely dangerous situation which could have disastrous results if the leaked cryogenic fluid should be ignited.
Insofar as is known to applicants, there are no tanks in the prior art capable of both maintaining an effective seal for the cryogenic fluids and at the same time providing an impact resisting means to withstand explosions or impact loads thereon. Thus, there is an urgent need for a storage tank for cryogenic fluids which includes means for both maintaining an efficient confinement for the cryogenic fluid and also for resisting impact loads thereon.